Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine.
Abstract:The distribution and abundance of marine organisms are directly or indirectly a function of biotic and abiotic features such as sediment and water properties. In this study we analyzed the spatial and temporal distribution of Callinectes danae in two distinct littoral areas of the northern coast of the State of São Paulo, Brazil and associated them with local geomorphologic features and environmental factors. We collected specimens on a monthly basis, from July 2001 to June 2003, using a fishing boat equipped with double-rig net, in two locations: Ubatuba (UBA) and Caraguatatuba (CAR). Collecting was carried out in seven transects with different depths, which were further subdivided into two regions: bay region (5, 10, 15 and 20 m deep); and inner shelf region (25, 30 and 35 m deep). Samples from different periods and transects differed significantly in abundance. A positive correlation was found between the abundance of C. danae and the following parameters: temperature at the bottom, organic matter content and Phi (grain diameter). By contrast, a negative correlation was established between specimen abundance and salinity at the bottom. The total abundance was highest in 5 m deep transects in both regions. Summer was the season when individuals were least abundant in both areas. We concluded that the spatial and temporal distribution of C. danae are determined by a set of environmental factors and not just by one single factor.
RESUMO Testaram-se as hipóteses de que, assim como em reservatórios de grande áreas de superfície, volumes e vazão, em reservatórios pequenos também ocorrem a diluição gradual e contínua da riqueza, da diversidade e abundância de microcrustáceos (Cladocera e Copepoda) a jusante dos mesmos, sem a recomposição da riqueza a jusante pela falta de rios tributários, lagoas marginais e até pelo pequeno porte do riacho, sem condições para o desenvolvimento do potamoplâncton próprio do sistema. Foram estudados dois pequenos reservatórios e seus trechos a jusante, com coletas diárias a cada seis horas em oito pontos de amostragem, sendo dois lênticos e seis lóticos a jusante de cada. Foram encontradas 19 espécies (11 de Cladocera e oito de Copepoda), com destaque para o maior número de espécies litorâneas do que pelágicas, e a maior abundância de cladóceros litorâneos nos pontos a jusante dos reservatórios. Não houve diferença entre os horários, indicando que a escala espacial foi mais importante que a temporal. Houve maiores valores dos atributos ecológicos nos ambientes lênticos, porém houve aumentos significativos de riqueza e diversidade nos últimos pontos dos trechos de riacho, enquanto que a abundância diminuiu gradativamente a jusante. Não foram encontradas correlações significativas da abundância dos táxons com nenhuma variável limnológica (temperatura, pH, oxigênio dissolvido, turbidez, sólidos totais dissolvidos e transparência), indicando pouco ou nenhum efeito destas variáveis. A análise de cluster com distância euclidiana separou dois grandes grupos, o primeiro formado pelo trecho a jusante do primeiro reservatório e o segundo com os demais pontos. Além da presença dos táxons litorâneos vindos dos reservatórios, houve incremento de táxons litorâneos residentes nos riachos. Pode-se concluir que houve uma diluição da abundância das espécies a jusante dos riachos, mas a riqueza e a diversidade permaneceram estáveis devido à contribuição de táxons litorâneos.
We present here the first study that analyzed the composition and richness of rotifers of the entire La Plata River basin, the second largest in South America, based on simultaneous and standardized sampling. Fifteen large reservoirs and eight river stretches were selected in the upper, middle, and lower portions of the Paraná, Paraguay, and Uruguay Rivers, which are the major rivers of the La Plata basin. We took a total of 86 samples (open water habitats) in 2010. A mean of 27±11 species per sub-basin was found, with the highest richness in the Lower Paraná (41 species), followed by the Paranapanema (40 species) and Lower Uruguay (38 species). Low richness was observed in the Middle Uruguay and Middle Paraná. We found 106 species belonging to 21 families and two orders. The family with the highest number of species was Lecanidae (21), followed by Brachionidae (20), Trichocercidae (9), and Synchaetidae (8). The species with higher occurrences were Conochilus dossuarius, Kellicottia bostoniensis, Keratella americana, Keratella cochlearis and Hexarthra mira. New occurrences of rotifers were registered for Brazil (Colurella adriatica), São Paulo State (Enteroplea lacustris), and Argentina (Gastropus hyptopus, Harringia rousseleti and Lecane thienemanni). Spearman correlation between the number of species and physical and chemical variables demonstrated positive correlation with chlorophyll and temperature, and negative correlation with dissolved oxygen. We extend the distribution list for some native (Lecane ludwigii) and non-native species of rotifers (K. bostoniensis). We also list the monogonont rotifer species found at the sampling stations.
The hight extractivism of marine fish to supply the demand of the aquarium market has worried the researchers and, in this context,, the aquaculture consists of an alternative to the problem. The family Chaetodontidae represents one of the main families of ornamental marine fish and has not received enough attention on their cultivation research. Considering the absence of this information about the butterflyfish Chaetodon striatus, the present work had the objective of obtaining information about the species in captivity. The fishes were kept in tanks of 100, 200, 300 and 1,000 L, with 6 fishes in each tank, with 3 repetitions for each volume, totaling 72 individuals and were observed for 30 days, being offered living small invertebrates and frozen and fresh mussels for the feeding. Also, for the attempt of reproduction in captivity, two couples, collected directly from the sea, with the entry of only two adults in the trap at a time, were used. Each couple was acclimated in a 100 L tank and we observed their behaviors for 8 hours a day. There was no mortality in tanks of 300 and 1,000 L and, for feeding, small invertebrates and fresh mussels were well accepted. Some behaviors were observed, most of which were already described for chaetodontids. This is the first report of C. striatus in captivity and this contribution may provide subsidies for a future technological package.
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